A manufacturing method of a unit fuel cell (single cell) of a fuel cell is proposed in for example JP-A-2002-246044. This unit fuel cell manufacturing method will be described on the basis of FIG. 19 hereof.
Referring to FIG. 19, a unit fuel cell 300 has a membrane electrode structure 301 formed by providing positive and negative electrodes 303, 304 on the faces of an electrolyte membrane 302. Separators 305, 306 are provided on the faces of this membrane electrode structure 301.
For this unit fuel cell 300 to produce electricity, fuel gas and oxygen gas must be supplied to inside the unit fuel cell 300. To keep the supplied fuel gas and oxygen gas inside the unit fuel cell 300, the periphery of the unit fuel cell 300 must be sealed.
To this end, the electrolyte membrane 302 is made to project outward of the peripheries of the positive and negative electrodes 303, 304, and peripheral parts 308, 309 of the separators 305, 306 are made to face this projecting part 307. Channels 311, 312 are formed in the peripheral parts 308, 309, and liquid seals 313, 313 are deposited in the channels 311, 312.
By the separators 305, 306 with the liquid seals 313, 313 applied being placed on the sides of the membrane electrode structure 301 and the liquid seals 313, 313 being solidified, the gaps 314, 314 between the separators 305, 306 and the electrolyte membrane 302 are sealed.
Many of these unit fuel cells 300 in a stack constitute a fuel cell. That is, a fuel cell has a structure wherein multiple unit fuel cells 300 are stacked to form a stack 316, a first support plate (not shown) is provided on one end of the stack 316, a second support plate (not shown) is provided on the other end of the stack 316, and the stack 316 is held in a pressed state by the first and second support plates being connected together with connection members.
Now, to secure electricity-producing capacity of the fuel cell, it is necessary for the hydrogen gas and oxygen gas necessary for electricity generation to be supplied well and for water produced during electricity generation to be drained well. For this, it is important for gas supply passages 318 for supplying hydrogen gas and oxygen gas and water-draining passages 319 for draining water away to be provided well.
To provide these gas supply passages 318 and water-draining passages 319 in the stack 316, gas supply channels 321 and water-draining channels 322 are pre-formed in the separators 305, 306, and when the separators 305, 306 are stacked the openings of the gas supply channels 321 and the openings of the water-draining channels 322 are closed to make them into flow passages 318, 319.
To secure these gas supply passages 318 and water-draining passages 319 well, when the stack 316 is manufactured, it is necessary for the unit fuel cells 300 to be stacked in a well-aligned state.
Additionally, by the stack 316 being held in a pressed state, the liquid seals 313, 313 of the unit fuel cells 300 are compressed. When the liquid seals 313, 313 are compressed, if the unit fuel cells 300 are not well aligned, it is difficult to apply a uniform pressing force to the liquid seals 313, 313, it is likely that large pressing forces will act locally on the liquid seals 313, 313, and considered from points of view such as that of the durability of the liquid seals 313, 313 this is undesirable.
Accordingly, to apply a uniform pressing force to the liquid seals 313, 313, it is necessary to stack the multiple unit fuel cells 300 in a well-aligned state.
However, the work of stacking the multiple unit fuel cells 300 to make the stack 316 is normally carried out by a worker by hand. Consequently, when stacking the multiple unit fuel cells 300, the worker must handle the individual unit fuel cells 300 carefully, and there is an excessive burden on the worker and this has been a hindrance to raising productivity.
Accordingly, a fuel cell manufacturing method and manufacturing apparatus have been awaited with which it is possible to lighten the burden on the worker and raise productivity.